Effect of Sodium-Glucose Co-Transporter 2 Inhibitors Combined with Metformin on Pancreatic Cancer Cell Lines.

Pancreatic cancer (PC) is the ninth-leading cause of cancer-related deaths worldwide. Diabetic patients have an increased risk and mortality rates for PC. Sodium-glucose co-transporter 2 (SGLT2) inhibitors and metformin (Met) are widely used anti-diabetic medications. Both Met and SGLT2 inhibitors have anticancer properties in PC, but nothing is known concerning their combined effect. So, we investigated the in vitro effect of SGLT2 inhibitors combined with Met. Canagliflozin and dapagliflozin possessed cytotoxic, antiproliferative, and pro-apoptotic properties in the tested PC cell lines. In PANC-1 cells, the antimigratory and pro-apoptotic effects were enhanced when dapagliflozin was combined with Met, and G1 cell cycle arrest was enhanced when dapagliflozin or canagliflozin was combined with Met. In AsPC-1 cells, the cytotoxic effect and the G1 cell cycle arrest were enhanced when canagliflozin and dapagliflozin, respectively, were combined with Met. Only the cytotoxic effects of SGLT2 inhibitors, but not the combination treatments, involved PI3K and JNK-dependent pathways in AsPC-1 cells. In conclusion, combination treatments increased the anticancer effects in a cell type-dependent way in the two investigated cell lines. Additionally, the cytotoxic effect of SGLT2 inhibitors was dependent on the PI3K and JNK pathways in AsPC-1 cells, but Met appears to act via a distinct mechanism.

Additive Cytotoxic and Colony-Formation Inhibitory Effects of Aspirin and Metformin on PI3KCA-Mutant Colorectal Cancer Cells.

Human malignancies are one of the major health-related issues throughout the world and are anticipated to rise in the future. Despite huge investments made in anticancer drug development, limited success has been obtained and the average number of FDA approvals per year is declining. So, an increasing interest in drug repurposing exists. Metformin (MET) and aspirin (ASP) possess anticancer properties. This work aims to test the effect of these two drugs in combination on colorectal cancer (CRC) cells in vitro. The effects of MET and/or ASP on cell proliferation, viability, migratory ability, anchorage-independent growth ability (colony formation), and nutrient uptake were determined in two (HT-29 and Caco-2) human CRC cell lines. Individually, MET and ASP possessed antiproliferative, cytotoxic, and antimigratory effects and reduced colony formation in HT-29 cells (BRAF- and phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit α (PI3KCA)-mutant), although MET did not affect either 3H-deoxy-D-glucose or 14C-butyrate uptake and lactate production, and ASP caused only a small decrease in 14C-butyrate uptake. Moreover, in these cells, the combination of MET and ASP resulted in a tendency to an increase in the cytotoxic effect and in a potentiation of the inhibitory effect on colony formation, although no additive antiproliferative and antimigratory effects, and no effect on nutrient uptake and lactate production were observed. In contrast, MET and ASP, both individually and in combination, were almost devoid of effects on Caco-2 cells (BRAF- and PI3KCA-wild type). We suggest that inhibition of PI3K is the common mechanism involved in the anti-CRC effect of both MET, ASP and their combination and, therefore, that the combination of MET + ASP may especially benefit PI3KCA-mutant CRC cases, which currently have a poor prognostic.

Metabolic effects of atypical antipsychotics: Molecular targets.

Atypical antipsychotics (AAPs) are commonly prescribed drugs in the treatment of schizophrenia, bipolar disorder and other mental diseases with psychotic traits. Although the use of AAPs is associated with beneficial effects in these patients, they are also associated with undesired metabolic side effects, including metabolic syndrome (MetS). MeS is defined by the presence of metabolic abnormalities such as large waist circumference, dyslipidemia, fasting hyperglycemia and elevated blood pressure, which predispose to type 2 diabetes (T2D) and cardiovascular disease. In this review, the molecular and cellular mechanisms involved in these undesired metabolic abnormalities induced by AAPs are described. These mechanisms are complex as AAPs have multiple cellular targets which significantly affect the activities of several hormones and neuromodulators. Additionally, AAPs affect all the relevant metabolic organs, namely the liver, pancreas, adipose tissue, skeletal muscle and intestine, and the central and peripheral nervous system as well. A better understanding of the molecular targets linking AAPs with MetS and of the mechanisms responsible for clinically different side effects of distinct AAPs is needed. This knowledge will help in the development of novel AAPs with less adverse effects as well as of adjuvant therapies to patients receiving AAPs.

Taurocholate uptake by Caco-2 cells is inhibited by pro-inflammatory cytokines and butyrate.

Inflammatory bowel disease (IBD) is a group of chronic and life-threating inflammatory diseases of the gastrointestinal tract. The active intestinal absorption of bile salts is reduced in IBD, resulting in higher luminal concentrations of these agents that contribute to the pathophysiology of IBD-associated diarrhea. Butyrate (BT) is a short-chain fatty acid produced by colonic bacterial fermentation of dietary fibers. BT utilization is impaired in the intestinal inflamed mucosa of IBD patients. Our aim was to investigate the link between IBD and bile acid absorption, by testing the effect of the pro-inflammatory cytokines TNF-α and IFN-γ and of BT upon 3H-TC uptake by Caco-2 cells. The proinflammatory cytokines TNF-α and IFN-γ inhibit Na+-independent, non-ASBT (sodium-dependent bile acid transporter)-mediated 3H-TC uptake by Caco-2 cells. The inhibitory effect of these cytokines on Na+-independent 3H-TC uptake is PI3K- and JAK/STAT1-mediated. These two compounds upregulate ASBT expression levels, but no corresponding increase in Na+-dependent component of 3H-TC is observed. Moreover, BT was also found to inhibit 3H-TC uptake and showed an additive effect with IFN-γ in reducing 3H-TC uptake. We conclude that an interaction between BT and bile acids appears to exist in IBD, which may participate in the link between diet, microbiota and IBD.

Bile salts and proinflammatory cytokines inhibit MCT1-mediated cellular uptake of butyrate and interfere with its antiproliferative properties.

Butyrate (BT) is important in the prevention and inhibition of colorectal cancer (CRC). Inflammatory bowel disease, a risk factor for CRC, is associated with higher levels of proinflammatory cytokines and bile acids. The aim of this work was to investigate the interaction of these compounds in inhibiting BT uptake by Caco-2 cells, as a mechanism contributing to the link between IBD and CRC. TNF-α, IFN-γ, chenodeoxycholic acid (CDCA) and deoxycholic acid (DCA) markedly reduce 14C-BT uptake. All these compounds appear to inhibit MCT1-mediated BT cellular uptake at a posttranscriptional level, and, because their effect is not additive, they are most probably inhibiting MCT1 by a similar mechanism. Correspondingly, the antiproliferative effect of BT (MCT1-dependent) and of the proinflammatory cytokines and CDCA were not additive. In contrast, the cytotoxic effect of BT (MCT1-independent) and of the proinflammatory cytokines and CDCA were additive. In conclusion, proinflammatory cytokines (TNF-α and IFN-γ) and bile acids (DCA and CDCA) inhibit MCT1-mediated BT cellular uptake. These proinflammatory cytokines and CDCA were found to interfere with the antiproliferative effect of BT, mediated by an inhibitory effect upon MCT1-mediated cellular uptake of BT.

Gallic acid markedly stimulates GLUT1-mediated glucose uptake by the AsPC-1 pancreatic cancer cell line.

Phenolic acids are recognized as chemopreventive and chemotherapeutic agents. Altered glucose and glutamine metabolism are recognized hallmarks of cancer cells. We aimed to test the influence of phenolic acids on glucose and glutamine cellular uptake by a breast (MCF-7) and a pancreatic (AsPC-1) cancer cell line. Several phenolic acids (caffeic, ferrulic, proctocatechuic, coumaric and gallic acid) affected 3H-glutamine and/or 3H-deoxy-d-glucose (3H-DG) uptake. Gallic acid (100 µM) caused a 3-fold increase in 3H-DG uptake by AsPC-1 cells, associated with a 3.7-fold increase in lactic acid production. Gallic acid stimulated GLUT1-mediated 3H-DG uptake and increased the affinity of this transporter for 3H-DG. We further verified that gallic acid does not change GLUT1 transcription rates and cellular redox state and that its effect does not involve PI3K, mTOR and MAP kinases and is not associated with a proproliferative effect. Gallic acid also increased 3H-DG uptake by MCF-7 cells, although less potently. Further investigation is necessary to elucidate the cellular pathways involved in this effect of gallic acid.

Common pregnancy complications and polyphenols intake: an overview.

During pregnancy, the body undergoes a great amount of changes in order to support a healthy developing fetus. In this context, maternal dietary supplementation is widely encouraged to provide adequate nutrition for the newborn. In the past few years, studies have emerged highlighting the benefits of polyphenols intake during pregnancy. Indeed, despite differences among reports, such as experimental model, polyphenol employed, dosage and regimen of administration, there is no doubt that the ingestion of these molecules has a protective effect in relation to three pregnancy-associated diseases or conditions: preeclampsia, gestational diabetes and fetal growth restriction. In this review, we describe the effects of different polyphenols and polyphenol-rich extracts or juices on the main outcomes of these common pregnancy-associated complications, obtained in human, animal and in vitro studies. Therefore, this work provides a critical analysis of the literature, and a summary of evidences, from which future research using polyphenols can be designed and evaluated.

Inhibition of kidney potassium channels by fluoxetine: In vivo and in vitro studies.

In vitro studies have demonstrated that fluoxetine, a commonly used antidepressant drug, can modulate the activity of K+ channels. In the present study, we investigated the in vivo effect of acute and sub-chronic treatment of rats with fluoxetine on K+ renal transport. Furthermore, OK cells, a kidney epithelial cell line, were used in order to evaluate the in vitro effect of fluoxetine on K+ currents. In the sub-chronic study, fluoxetine was administrated daily (10 mg/kg, p.o.) for 15 days to male adult Wistar rats. In the acute study, rats were given increasing doses of fluoxetine (1, 3, 10, 30 and 50 mg/kg, p.o.) for 24 h. Results from the sub-chronic study show that urinary K+ content (in mmol/L) was markedly reduced in the fluoxetine-treated animals (fluoxetine: 83 ± 9; control: 131 ± 10; P < 0.001). K+ fractional renal excretion (in %) was also significantly lower in the fluoxetine group (fluoxetine: 6 ± 1; control: 13 ± 2; P < 0.001). No significant changes was observed in creatinine clearance and on renal tubular Na+ ,K+ -ATPase activity. Results obtained from the acute study demonstrate that, after a 24-h administration, fluoxetine produced a dose-dependent decrease in urinary K+ , with an ED50 (in mg/kg) of 4.2 (2.8; 5.5) and a maximal effect of 62% reduction. In vitro, fluoxetine produced a concentration-dependent inhibition of K+ currents in OK cells, with an EC50 of 107 (84.8; 129.5) µM. In conclusion, fluoxetine produces a marked reduction on urinary K+ excretion; this effect constitutes an in vivo evidence for the inhibitory action of fluoxetine on kidney epithelial K+ channels.

A Prunus avium L. Infusion Inhibits Sugar Uptake and Counteracts Oxidative Stress-Induced Stimulation of Glucose Uptake by Intestinal Epithelial (Caco-2) Cells.

Sweet cherry (Prunus avium L.) is among the most valued fruits due to its organoleptic properties and nutritional worth. Cherry stems are rich in bioactive compounds, known for their anti-inflammatory and antioxidant properties. Innumerable studies have indicated that some bioactive compounds can modulate sugar absorption in the small intestine. In this study, the phenolic profile of a cherry stem infusion was investigated, as well as its capacity to modulate intestinal glucose and fructose transport in Caco-2 cells. Long-term (24 h) exposure to cherry stem infusion (25%, v/v) significantly reduced glucose (3H-DG) and fructose (14C-FRU) apical uptake, reduced the apical-to-basolateral Papp to 3H-DG, and decreased mRNA expression levels of the sugar transporters SGLT1, GLUT2 and GLUT5. Oxidative stress (induced by tert-butyl hydroperoxide) caused an increase in 3H-DG uptake, which was abolished by the cherry stem infusion. These findings suggest that cherry stem infusion can reduce the intestinal absorption of both glucose and fructose by decreasing the gene expression of their membrane transporters. Moreover, this infusion also appears to be able to counteract the stimulatory effect of oxidative stress upon glucose intestinal uptake. Therefore, it can be a potentially useful compound for controlling hyperglycemia, especially in the presence of increased intestinal oxidative stress levels.

Polymeric Materials as Indispensable Tools to Fight RNA Viruses: SARS-CoV-2 and Influenza A.

Towards the end of 2019 in Wuhan, suspicions of a new dangerous virus circulating in the air began to arise. It was the start of the world pandemic coronavirus disease 2019 (COVID-19). Since then, considerable research data and review papers about this virus have been published. Hundreds of researchers have shared their work in order to achieve a better comprehension of this disease, all with the common goal of overcoming this pandemic. The coronavirus is structurally similar to influenza A. Both are RNA viruses and normally associated with comparable infection symptoms. In this review, different case studies targeting polymeric materials were appraised to highlight them as an indispensable tool to fight these RNA viruses. In particular, the main focus was how polymeric materials, and their versatile features could be applied in different stages of viral disease, i.e., in protection, detection and treatment.

Green/Roasted Coffee and Silverskin Extracts Inhibit Sugar Absorption by Human Intestinal Epithelial (Caco-2) Cells by Decreasing GLUT2 Gene Expression.

Moderate coffee ingestion has been associated with a decrease in type 2 diabetes risk, mainly due to its richness in chlorogenic acids (CGA). To explore this, extracts of green beans, roasted beans, and silverskin were prepared by aqueous ultrasound-assisted extraction and characterized by a reversed-phase high-performance liquid chromatography-photodiode array detector (RP-HPLC-DAD). The effects on the uptake of glucose and fructose by human intestinal epithelial (Caco-2) cells and the influence on the expression of sugar transporter genes (by RT-qPCR) were investigated and compared. The uptake of 3H-deoxy-D-glucose and 14C-fructose by Caco-2 cells was significantly reduced by all the extracts, with green coffee (which also contained higher amounts of CGA) achieving the highest efficiency. Although silverskin presented the lowest amounts of CGA and caffeine, it promoted an inhibitory effect similar to the effects of green/roasted beans. In the case of glucose uptake, the effect was even higher than for roasted coffee. This activity is explained by the ability of the extracts to markedly decrease GLUT2, but not GLUT5 gene expression. In addition, a decrease in SGLT1 gene expression was also found for all extracts, although not at a statistically significant rate for silverskin. This study also revealed a synergistic inhibitory effect of caffeine and 5-CQA on the uptake of sugars. Thus, silverskin appears as an interesting alternative to coffee, since the valorization of this by-product also contributes to the sustainability of the coffee chain.

Can coffee silverskin be a useful tool to fight metabolic syndrome?

Coffee is one of the most consumed products in the world, and its by-products are mainly discarded as waste. In order to solve this problem and in the context of a sustainable industrial attitude, coffee by-products have been studied concerning their chemical and nutritional features for a potential application in foodstuffs or dietary supplements. Under this perspective, coffee silverskin, the main by-product of coffee roasting, stands out as a noteworthy source of nutrients and remarkable bioactive compounds, such as chlorogenic acids, caffeine, and melanoidins, among others. Such compounds have been demonstrating beneficial health properties in the context of metabolic disorders. This mini-review compiles and discusses the potential health benefits of coffee silverskin and its main bioactive components on metabolic syndrome, highlighting the main biochemical mechanisms involved, namely their effects upon intestinal sugar uptake, glucose and lipids metabolism, oxidative stress, and gut microbiota. Even though additional research on this coffee by-product is needed, silverskin can be highlighted as an interesting source of compounds that could be used in the prevention or co-treatment of metabolic syndrome. Simultaneously, the valorization of this by-product also responds to the sustainability and circular economy needs of the coffee chain.

Effects of Cannabidiol on Appetite and Body Weight: A Systematic Review.

BACKGROUND AND OBJECTIVE: Cannabidiol, one of the main components of the Cannabis sativa plant, is a non-psychotropic cannabinoid that has recently drawn the attention of researchers and clinicians for its potential therapeutic applications. In this systematic review, we aim to describe the possible effects of cannabidiol in appetite and body weight. METHODS: Both authors independently ran a thorough search in both PubMed and Cochrane databases up to 31 July, 2022 and included every peer-reviewed, original randomized controlled clinical trial that reported data on either of the said outcomes. Risk of assessment bias was performed with Cochrane's risk of bias tool and results were summarized in tables. RESULTS: A total of 11 trials were included in this review. Of these, the majority reported on cannabidiol reducing appetite and/or body weight whilst some have found no significant changes and one trial described an increase in appetite. CONCLUSIONS: This systematic review suggests that cannabidiol has an anorexigenic effect, correlated with a decrease in body weight. However, most of the studies included in the present review raised some concerns in terms of risk of bias. We believe further research is needed in order to clarify potential mechanisms involved in the effect of cannabidiol on feeding/appetite.

The effects of aspartame on the HTR8/SVneo extravillous trophoblast cell line.

Extravillous trophoblasts (EVTs) are a key cell type involved in placentation. Aspartame is an artificial sweetener with a widespread use. In rodents, aspartame ingestion during pregnancy was found to cause a reduction in placental and fetal weights, but its effect in placentation at a cellular level has not been studied. Aspartame is completely hydrolyzed in the gastrointestinal tract into L-phenylalanine, L-aspartic acid, and methanol. We aimed to study the effects of aspartame and its metabolites on placentation related characteristics of EVTs. For this, we exposed HTR-8/SVneo cells to aspartame (0.001, 0.01, 0.1, 0.5 and 1 mM), L-phenylalanine (0.14 and 0.5 mM), L-aspartic acid (0.82, 2.8 and 10 mM) or methanol (0.14 and 0.8 mM) for 24 h. Aspartame had an anti-proliferative effect, decreased the number of metabolically active cells and glucose cellular uptake and increased the number of cells arrested in S phase. L-aspartic acid significantly reduced glucose uptake and whole-cell protein content. L-phenylalanine had an anti-proliferative effect and increased the number of metabolically active cells. Interestingly, methanol exerted very marked effects on HTR8/SVneo cells: it showed an anti-proliferative effect, decreased glucose uptake, the migratory ability and the number of cells in the G2/M phase and increased oxidative stress levels, in concentrations corresponding to the blood levels after the 99th percentile of projected daily ingestion of aspartame. Overall, our results demonstrate that aspartame and its metabolites can affect several characteristics of EVTs and support the conclusion that the effect of aspartame in the placenta should be further evaluated.

Valorizing Coffee Silverskin Based on Its Phytochemicals and Antidiabetic Potential: From Lab to a Pilot Scale.

This study investigates the possibility of valorizing coffee silverskin through the recovery of its bioactive compounds using a sustainable extraction method that could be industrially applied. For that, aqueous extracts were prepared using ultrasonic-assisted extraction (laboratorial scale) and, for comparison, a scale-up of the process was developed using the Multi-frequency Multimode Modulated technology. A concentration procedure at the pilot scale was also tested. The three types of extracts obtained were characterized regarding caffeine and chlorogenic acids contents, and the effects on intestinal glucose and fructose uptake (including sugar transporters expression) in human intestinal epithelial (Caco-2) cells were ascertained. The phytochemical contents of the extracts prepared at the laboratory and pilot scale were comparable (caffeine: 27.7 vs. 29.6 mg/g freeze-dried extract; 3-, 4-, and 5-caffeoylquinic acids: 0.19 vs. 0.31, 0.15 vs. 0.42, and 1.04 vs. 1.98 mg/g, respectively; 4- and 5- feruloylquinic acids: 0.39 vs. 0.43 and 1.05 vs. 1.32 mg/g, respectively). Slight differences were noticed according to the extracts preparation steps, but in general, all the extracts promoted significant inhibitions of [1,2-3H(N)]-deoxy-D-glucose and 14C-D-fructose uptake, which resulted mainly from a decrease on the facilitative glucose transporter 2 (GLUT2) and sodium-glucose linked transporter 1 (SGLT1) genes expression but not on the expression of the facilitative glucose transporter 5 (GLUT5) gene. Moreover, a synergistic effect of caffeine and 5-caffeoylquinic acid on sugars uptake was found. The results clearly show that the Multi-frequency Multimode Modulated technology is a viable option to be applied at an industrial level to recover bioactive components from silverskin and obtain extracts with antidiabetic potential that could be used to develop functional food products or dietary supplements.

NSAID-Based Coordination Compounds for Biomedical Applications: Recent Advances and Developments.

After the serendipitous discovery of cisplatin, a platinum-based drug with chemotherapeutic effects, an incredible amount of research in the area of coordination chemistry has been produced. Other transition metal compounds were studied, and several new relevant metallodrugs have been synthetized in the past few years. This review is focused on coordination compounds with first-row transition metals, namely, copper, cobalt, nickel or manganese, or with zinc, which have potential or effective pharmacological properties. It is known that metal complexes, once bound to organic drugs, can enhance the drugs' biological activities, such as anticancer, antimicrobial or anti-inflammatory ones. NSAIDs are a class of compounds with anti-inflammatory properties used to treat pain or fever. NSAIDs' properties can be strongly improved when included in complexes using their compositional N and O donor atoms, which facilitate their coordination to metal ions. This review focuses on the research on this topic and on the promising or effective results that complexes of first-row transition metals and NSAIDs can exhibit.

α-tocopherol prevents oxidative stress-induced proliferative dysfunction in first-trimester human placental (HTR-8/SVneo) cells.

Extravillous trophoblasts (EVTs) are the main participants in the process of placentation, an early process critical for placental growth and function involving an adequate invasion and complete remodelling of the maternal spiral arteries during early pregnancy. An increase in oxidative stress during pregnancy is associated with the onset and progression of several pregnancy disorders, including preeclampsia and gestational diabetes mellitus and it also occurs due to exposure of pregnant women to some xenobiotics (eg. alcohol). This study aimed to investigate how oxidative stress affects EVTs, and the ability of several distinct antioxidant agents to prevent these changes. For this, we exposed HTR8/SVneo cells to tert-butylhydroperoxide (0.5 µM; 24 h), which was able to increase lipid peroxidation and protein carbonyl levels. Under these conditions, there was a decrease in proliferation rates, culture growth, migratory and angiogenic capacities and an increase in the apoptosis rates. The antiproliferative effect of TBH was supressed by simultaneous treatment of the cells with α-tocopherol, but other antioxidants (vitamin C, allopurinol, apocynin, N-acetylcysteine, quercetin and resveratrol) were ineffective. α-tocopherol was also able to abolish the effect of TBH on lipid peroxidation and protein carbonyl levels. Overall, our results show that oxidative stress interferes with EVT characteristics essential for the placentation process, which may contribute to the association between oxidative stress and pregnancy disorders. Our results also show that the nature of the in vitro model of oxidative stress-induction is an important determinant of the cellular consequences of oxidative stress and, therefore, of the efficacy of antioxidants.

The pro-proliferative effect of insulin in human breast epithelial DMBA-transformed and non-transformed cell lines is PI3K-, mTOR- and GLUT1-dependent.

Type 2 diabetes mellitus (T2DM) is linked to an increased risk of breast cancer. We aimed to investigate how T2DM-associated characteristics (high levels of glucose, insulin, leptin, inflammatory mediators and oxidative stress) influence breast cancer carcinogenesis, in DMBA-treated (MCF-12ADMBA ) and non-treated breast epithelial (MCF-12A) cell lines. Insulin (50 nM) promotes cell proliferation, 3 H-DG uptake and lactic acid production in both cell lines. The stimulatory effects of insulin upon cell proliferation and 3 H-DG uptake were hampered by rapamycin, LY294001 and BAY-876, in both cell lines. In conclusion, hyperinsulinemia, one important characteristic of T2DM, contributes to the initiation of breast cancer by a PI3K- and mTOR-dependent mechanism involving increased GLUT1-mediated glucose uptake. SIGNIFICANCE: The pro-proliferative effect of insulin in human breast epithelial DMBA-transformed and non-transformed cell lines is PI3K-, mTOR- and GLUT1-dependent.

Silica-Based Nanomaterials for Diabetes Mellitus Treatment.

Diabetes mellitus, a chronic metabolic disease with an alarming global prevalence, is associated with several serious health threats, including cardiovascular diseases. Current diabetes treatments have several limitations and disadvantages, creating the need for new effective formulations to combat this disease and its associated complications. This motivated the development of therapeutic strategies to overcome some of these limitations, such as low therapeutic drug bioavailability or poor compliance of patients with current therapeutic methodologies. Taking advantage of silica nanoparticle characteristics such as tuneable particle and pore size, surface chemistry and biocompatibility, silica-based nanocarriers have been developed with the potential to treat diabetes and regulate blood glucose concentration. This review discusses the main topics in the field, such as oral administration of insulin, glucose-responsive devices and innovative administration routes.

The pro-proliferative effect of interferon-γ in breast cancer cell lines is dependent on stimulation of ASCT2-mediated glutamine cellular uptake.

AIMS: Type 2 diabetes mellitus (T2DM) is a risk factor for breast cancer initiation and progression. Glutamine (GLN) is a critical nutrient for cancer cells. The aim of this study was to investigate the effect of T2DM-associated compounds upon GLN uptake by breast cancer cells. MAIN METHODS: The in vitro uptake of 3H-GLN by breast cancer (MCF-7 and MDA-MB-231) and non-tumorigenic (MCF-12A) cell lines was measured. KEY FINDINGS: 3H-GLN uptake in the three cell lines is mainly Na+-dependent and sensitive to the ASCT2 inhibitor GPNA. IFN-γ increased total and Na+-dependent 3H-GLN uptake in the two breast cancer cell lines, and insulin increased total and Na+-dependent 3H-GLN uptake in the non-tumorigenic cell line. GPNA abolished the increase in 3H-GLN uptake promoted by these T2DM-associated compounds. ASCT2 knockdown confirmed that the increase in 3H-GLN uptake caused by IFN-γ (in breast cancer cells) and by insulin (in non-tumorigenic cells) is ASCT2-dependent. IFN-γ (in MDA-MB-231 cells) and insulin (in MCF-12A cells) increased ASCT2 transcript and protein levels. Importantly, the pro-proliferative effect of IFN-γ in breast cancer cell lines was associated with an increase in 3H-GLN uptake which was GPNA-sensitive, blocked by ASCT2 knockdown and mediated by activation of the PI3K-, STAT3- and STAT1 intracellular signalling pathways. SIGNIFICANCE: IFN-γ and insulin possess pro-proliferative effects in breast cancer and non-cancer cell lines, respectively, which are dependent on an increase in ASCT2-mediated glutamine transport. Thus, an effective inhibition of ASCT2-mediated glutamine uptake may be a therapeutic strategy against human breast cancer in T2DM patients.